<?php

require_once 'HTMLPurifier/AttrDef.php';
require_once 'HTMLPurifier/URIParser.php';
require_once 'HTMLPurifier/URIScheme.php';
require_once 'HTMLPurifier/URISchemeRegistry.php';
require_once 'HTMLPurifier/AttrDef/URI/Host.php';
require_once 'HTMLPurifier/PercentEncoder.php';
require_once 'HTMLPurifier/AttrDef/URI/Email.php';

// special case filtering directives 

HTMLPurifier_ConfigSchema::define(
	'URI', 'Munge', null, 'string/null', '
<p>
	Munges all browsable (usually http, https and ftp)
	absolute URI\'s into another URI, usually a URI redirection service.
	This directive accepts a URI, formatted with a <code>%s</code> where 
	the url-encoded original URI should be inserted (sample: 
	<code>http://www.google.com/url?q=%s</code>).
</p>
<p>
	Uses for this directive:
</p>
<ul>
	<li>
		Prevent PageRank leaks, while being fairly transparent 
		to users (you may also want to add some client side JavaScript to 
		override the text in the statusbar). <strong>Notice</strong>:
		Many security experts believe that this form of protection does not deter spam-bots. 
	</li>
	<li>
		Redirect users to a splash page telling them they are leaving your
		website. While this is poor usability practice, it is often mandated
		in corporate environments.
	</li>
</ul>
<p>
	This directive has been available since 1.3.0.
</p>
');

// disabling directives

HTMLPurifier_ConfigSchema::define(
	'URI', 'Disable', false, 'bool', '
<p>
	Disables all URIs in all forms. Not sure why you\'d want to do that 
	(after all, the Internet\'s founded on the notion of a hyperlink). 
	This directive has been available since 1.3.0.
</p>
');
HTMLPurifier_ConfigSchema::defineAlias('Attr', 'DisableURI', 'URI', 'Disable');

HTMLPurifier_ConfigSchema::define(
	'URI', 'DisableResources', false, 'bool', '
<p>
	Disables embedding resources, essentially meaning no pictures. You can 
	still link to them though. See %URI.DisableExternalResources for why 
	this might be a good idea. This directive has been available since 1.3.0.
</p>
');

/**
 * Validates a URI as defined by RFC 3986.
 * @note Scheme-specific mechanics deferred to HTMLPurifier_URIScheme
 */
class HTMLPurifier_AttrDef_URI extends HTMLPurifier_AttrDef
{
	
	var $parser;
	var $embedsResource;
	
	/**
	 * @param $embeds_resource_resource Does the URI here result in an extra HTTP request?
	 */
	function HTMLPurifier_AttrDef_URI($embeds_resource = false) {
		$this->parser = new HTMLPurifier_URIParser();
		$this->embedsResource = (bool) $embeds_resource;
	}
	
	function validate($uri, $config, &$context) {
		
		if ($config->get('URI', 'Disable')) return false;
		
		$uri = $this->parseCDATA($uri);
		
		// parse the URI
		$uri = $this->parser->parse($uri);
		if ($uri === false) return false;
		
		// add embedded flag to context for validators
		$context->register('EmbeddedURI', $this->embedsResource); 
		
		$ok = false;
		do {
			
			// generic validation
			$result = $uri->validate($config, $context);
			if (!$result) break;
			
			// chained filtering
			$uri_def =& $config->getDefinition('URI');
			$result = $uri_def->filter($uri, $config, $context);
			if (!$result) break;
			
			// scheme-specific validation 
			$scheme_obj = $uri->getSchemeObj($config, $context);
			if (!$scheme_obj) break;
			if ($this->embedsResource && !$scheme_obj->browsable) break;
			$result = $scheme_obj->validate($uri, $config, $context);
			if (!$result) break;
			
			// survived gauntlet
			$ok = true;
			
		} while (false);
		
		$context->destroy('EmbeddedURI');
		if (!$ok) return false;
		
		// back to string
		$result = $uri->toString();
		
		// munge entire URI if necessary
		if (
			!is_null($uri->host) && // indicator for authority
			!empty($scheme_obj->browsable) &&
			!is_null($munge = $config->get('URI', 'Munge'))
		) {
			$result = str_replace('%s', rawurlencode($result), $munge);
		}
		
		return $result;
		
	}
	
}


